| Carex muricata | GB, VC113 Channel Islands, Saint Ouen's Bay, Jersey | Louis Arsene | Botanical Society & Exchange Club of The British Isles | 1/6/1929 | E |
| Carex muricata subsp. pairae | GB, VC17 Surrey, West Horsley | Edward Charles Wallace | Botanical Society & Exchange Club of The British Isles | 28/6/1947 | SLBI |
| Carex muricata subsp. pairae | GB, VC62 North-east Yorkshire, Catton | Catherine Muriel Rob | Botanical Society & Exchange Club of The British Isles Catherine Muriel Rob | 1/7/1945 | SLBI |
| Carex muricata subsp. pairae | GB, VC62 North-east Yorkshire, Catton | Catherine Muriel Rob | Botanical Society & Exchange Club of The British Isles Catherine Muriel Rob | 1/7/1945 | BM |
| Carex muricata subsp. pairae | GB, VC65 North-west Yorkshire, Coverham | Catherine Muriel Rob | Botanical Society & Exchange Club of The British Isles Catherine Muriel Rob | 4/7/1945 | SLBI |
| Carex otrubae | GB, VC58 Cheshire, Mickle Trafford | Charles Waterfall | Botanical Society & Exchange Club of The British Isles Charles Waterfall Job Edward Lousley | 30/7/1929 | SLBI |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC14 East Sussex, Isfield | J K Pickard Job Edward Lousley | Botanical Society & Exchange Club of The British Isles Patrick Martin Hall | 25/6/1933 to 17/9/1933 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC17 Surrey, Newdigate | Edward Charles Wallace | Botanical Society & Exchange Club of The British Isles Edward Charles Wallace Patrick Martin Hall | 6/9/1933 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC19 North Essex, Easthorpe | George Charles Brown | Botanical Society & Exchange Club of The British Isles Charles Bailey | 27/6/1915 | MANCH |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC32 Northamptonshire, Old Head Wood | George Chester | Botanical Society & Exchange Club of The British Isles Robert Stephen Adamson | 12/7/1913 | BM |
| Carex pulicaris | GB, VC70 Cumberland, Dock Tarn | William Arthur Sledge | Botanical Society & Exchange Club of The British Isles William Arthur Sledge | 8/7/1944 | SLBI |
| Carex spicata | GB, VC23 Oxfordshire, Beckley | John Frederick Gustav Chapple | Botanical Society & Exchange Club of The British Isles Druce Herbarium, Oxford | 14/6/1932 | E |
| Carex vulpina | GB, VC23 Oxfordshire, Otmoor | John Frederick Gustav Chapple | Botanical Society & Exchange Club of The British Isles Druce Herbarium, Oxford Martin F Gardner & Sabina G Knees | 1/8/1936 1/8/1946 | E |
+ | Carex vulpina | GB, VC23 Oxfordshire, Otmoor | I J Thearle | Botanical Society & Exchange Club of The British Isles Druce Herbarium, Oxford | 1/8/1946 | MANCH |
| Carex vulpina | GB, VC33 East Gloucestershire, Gloucester GB, VC33 East Gloucestershire, Walham | Ernest Nelmes | Botanical Society & Exchange Club of The British Isles Ernest Nelmes | 22/6/1945 | SLBI |
| Carex x helvola | GB, VC92 South Aberdeenshire, Lochnagar | William Andrew Shoolbred | Botanical Society & Exchange Club of The British Isles William Andrew Shoolbred William Charles Barton | 21/7/1906 | BM |
+ | Caucalis platycarpos | GB, VC39 Staffordshire, Burton on Trent | George Claridge Druce | Botanical Society & Exchange Club of The British Isles George Claridge Druce | 7/1929 | MANCH |
+ | Centaurea calcitrapa | GB, VC19 North Essex, Colchester,Hythe Quay | George Charles Brown | Botanical Society & Exchange Club of The British Isles | 16/6/1914 | MANCH |
| Centaurea debeauxii subsp. nemoralis | GB, VC17 Surrey, West Horsley | Charles Edward Britton | Botanical Society & Exchange Club of The British Isles Charles Edward Britton | 23/7/1919 | SLBI |
+ | Centaurea nigra x jacea = C. x moncktonii | GB, VC17 Surrey, hort. West Barnes Merton, root from Epsom Downs, Surrey | Charles Edward Britton | Botanical Society & Exchange Club of The British Isles Willis Openshaw Howarth | 27/7/1924 | MANCH |
| Centaurea surrejana | GB, VC17 Surrey, Epsom Downs | Charles Edward Britton | Botanical Society & Exchange Club of The British Isles Charles Edward Britton | 7/8/1921 | SLBI |
+ | Centaurium tenuiflorum | GB, VC10 Isle of Wight, Newport | James Walter Long | Botanical Society & Exchange Club of The British Isles | 9/1927 | MANCH |
| Centaurium tenuiflorum | GB, VC10 Isle of Wight, River Medina | James Walter Long | Botanical Society & Exchange Club of The British Isles | 1915 1945 | SLBI |
+ | Chamaemelum nobile | GB, VC3 South Devon, Dartmouth (S of),Torcross | Charles Waterfall | Botanical Society & Exchange Club of The British Isles Charles Waterfall | 5/9/1921 | MANCH |
+ | Chamaemelum nobile | GB, VC111 Orkney, Birsay,Beaquoy | Henry Halcro Johnston | Botanical Society & Exchange Club of The British Isles Willis Openshaw Howarth | 29/9/1921 | MANCH |
| Chenopodium | GB, VC17 Surrey, Frensham, Great Pond | Gerald Mortimer Ash | Botanical Society & Exchange Club of The British Isles Gerald Mortimer Ash | 7/1945 | SLBI |
+ | Chenopodium murale | GB, VC1 West Cornwall, Newquay | Chambre Corker Vigurs | Botanical Society & Exchange Club of The British Isles Chambre Corker Vigurs | 12/1913 | MANCH |
+ | Chenopodium murale | GB, VC23 Oxfordshire, Oxford | George Claridge Druce | Botanical Society & Exchange Club of The British Isles George Claridge Druce | | MANCH |
+ | Chrysanthemum segetum | GB, VC20 Hertfordshire, Saint Ippolyts | Joseph Edward Little | Botanical Society & Exchange Club of The British Isles | 23/10/1926 | MANCH |
+ | Chrysanthemum segetum | GB, VC70 Cumberland Cultivated | | Botanical Society & Exchange Club of The British Isles Charles Bailey | 5/1913 | MANCH |
+ | Cicendia filiformis | GB, VC113 Channel Islands, Guernsey,L'Ancresse Common | | Botanical Society & Exchange Club of The British Isles | 9/1913 | MANCH |
| Cirsium arvense | GB, VC17 Surrey, Nonsuch Park | Edward Charles Wallace | Botanical Society & Exchange Club of The British Isles | 23/8/1946 | SLBI |
| Cirsium arvense | GB, VC17 Surrey, Nonsuch Park | Edward Charles Wallace | Botanical Society & Exchange Club of The British Isles | 23/8/1946 | SLBI |
+ | Cirsium tuberosum | GB, VC10 Isle of Wight, Newport | James Walter Long | Botanical Society & Exchange Club of The British Isles | 8/1936 | MANCH |
| Cochlearia officinalis | GB, VC6 North Somerset, Weston-super-Mare | Charles Waterfall | Botanical Society & Exchange Club of The British Isles Charles Waterfall Job Edward Lousley | 1/6/1931 | SLBI |
+ | Crepis mollis | GB, VC88 Mid Perthshire, Garth Castle | William Andrew Shoolbred | Botanical Society & Exchange Club of The British Isles William Andrew Shoolbred | 21/7/1913 | MANCH |
+ | Cuscuta epithymum | GB, VC12 North Hampshire, Ashmansworth | William Charles Barton | Botanical Society & Exchange Club of The British Isles Charles Bailey William Charles Barton | 18/9/1915 | MANCH |
+ | Cuscuta epithymum | GB, VC16 West Kent, Wrotham (E of),Pilgrim's Way | Job Edward Lousley | Botanical Society & Exchange Club of The British Isles William Harold Pearsall | 15/8/1934 | MANCH |
+ | Cuscuta epithymum | GB, VC16 West Kent, Wrotham (E of),Pilgrim's Way | Job Edward Lousley | Botanical Society & Exchange Club of The British Isles William Harold Pearsall | 15/8/1934 | MANCH |
+ | Cynodon dactylon | GB, VC1 West Cornwall, Saint Michael's Bay | Ezekiel George Varenne | Botanical Society & Exchange Club of The British Isles Charles Bailey | | MANCH |